Cryptology ePrint Archive: Report 2012/400

An Algebraic Fault Attack on the LED Block Cipher

Philipp Jovanovic and Martin Kreuzer and Ilia Polian

Abstract: In this paper we propose an attack on block ciphers where we combine techniques derived from algebraic and fault based cryptanalysis. The recently introduced block cipher LED serves us as a target for our attack. We show how to construct an algebraic representation of the encryption map and how to cast the side channel information gained from a fault injection into polynomial form. The resulting polynomial system is converted into a logical formula in conjunctive normal form and handed over to a SAT solver for reconstruction of the secret key. Following this approach we were able to mount a new, successful attack on the version of LED that uses a 64-bit secret key, requiring only a single fault injection.

Note: The contents of this paper were presented at the "Third international conference on Symbolic Computation and Cryptography (SCC 2012)" (http://scc2012.unican.es) and in the "Symbolic Computations and Post-Quantum Cryptography" Online Seminar (http://www.stevens.edu/algebraic/SCPQ/)